Resin compositions and a method of curing the same

ABSTRACT

A resin composition comprising a) a high molecular weight compound containing an average of 2 or more hydroxyl groups and an average of 2 or more epoxy groups per molecule and having a number average molecular weight of 3,000 to 200,000; b) a silane compound having an average of 1 or more alkoxysilane, silanol and acyloxysilane groups per molecule and having a number average molecular weight of 104 to 200,000; and c) a metal chelate compound, is curable at a relatively low temperature to yield a film having excellent resistance to weathering.

This is a division of application Ser. No. 08/112,311, filed Aug. 27,1993, U.S. Pat. No. 5,389,727, which is turn is a division ofapplication Ser. No. 07/672,792, filed Mar. 21, 1991, and now U.S. Pat.No. 5,284,919, which is turn is a division of application Ser. No.07/402,408, filed Sep. 5, 1989, and now U.S. Pat. No. 5,026,793.

The present invention relates to novel resin compositions and a methodof curing the same.

For the curing of resins containing hydroxyl groups as functionalgroups, methods employing diisocyanate compounds, melamine resin, etc.have theretofore been employed. However, with diisocyanates, theresulting films are generally inadequate in weather resistance and tendto undergo yellowing. Furthermore, the resin compositions have short potlives, not to speak of the toxicity problem associated withdiisocyanates.

When a melamine resin is employed, a high baking temperature over about140° C. is necessary and the resulting film is not as resistant to acidas desired.

It is an object of the present invention to provide novel hydroxylgroup-containing resin compositions which are curable at a sufficientlyhigh rate at a low temperature not exceeding 100° C. and a method ofcuring the same compositions.

It is another object of the invention to provide novel hydroxylgroup-containing resin compositions which are not only having goodcurability at low temperature but adapted to yield a cured film havingexcellent weather resistance, acid resistance and other physicalproperties and a method of curing the same compositions.

Other objects and advantages of the present invention will becomeapparent as the following description of the invention proceeds.

The present invention provides novel resin compositions and a method forcuring the same, all of which are described hereinafter and summarizedimmediately below.

(1) A resin composition comprising (A) a high molecular weight hydroxycompound containing an average of two or more hydroxyl groups permolecule and having a number average molecular weight of 3,000 to200,000, (B) an epoxy compound containing an average of two or moreepoxy groups per molecule and having a number average molecular weightof 120 to 200,000, (C) a silane compound containing an average of one ormore functional groups selected from the class consisting ofalkoxysilane, silanol and acyloxysilane groups per molecule and having anumber average molecular weight of 104 to 200,000, and (D) at least onemetal chelate compound selected from the class consisting of aluminumchelate compounds, titanium chelate compounds and zirconium chelatecompounds (hereinafter referred to as Invention I);

(2) a resin composition which comprises (A) said high molecular weighthydroxy compound, (E) a high molecular weight compound containing anaverage of two or more epoxy groups per molecule and an average of oneor more functional groups selected from the class consisting ofalkoxysilane, silanol and acyloxysilane groups per molecule and having anumber average molecular weight of 3,000 to 200,000, and (D) said metalchelate compound (hereinafter referred to as invention II);

(3) a resin composition which comprises (F) a high molecular weightcompound containing an average of two or more hydroxyl groups and anaverage of one or more functional groups selected from the classconsisting of alkoxysilane, silanol and acyloxysilane groups permolecule and having a number average molecular weight of 3,000 to200,000, (G) a low molecular weight compound containing an average oftwo or more epoxy groups per molecule and having a number averagemolecular weight of 240 to 5,000, and (D) said metal chelate compound(hereinafter referred to as Invention III);

(4) a resin composition which comprises (H) a high molecular weightcompound containing an average of two or more hydroxyl groups and anaverage of two or more epoxy groups per molecule and having a numberaverage molecular weight of 3,000 to 200,000, (C) said silane compound,and (D) said metal chelate compound (hereinafter referred to asInvention IV); and

(5) a method of curing a resin composition which comprises crosslinkingany of the resin compositions of Invention I through IV at a temperaturenot exceeding 100° C.

To overcome the aforementioned disadvantages of the prior arttechnologies, the inventor of the present invention did assiduous anddiligent studies for developing a hydroxyl group-containing resincomposition which is curable at low temperature to yield satisfactoryfilm properties. As a result, it was found that a high molecular weightcompound containing two or more hydroxyl groups per molecule may becaused to cure at a sufficiently high rate even at a low temperature notexceeding 100° C. when it is so arranged that the curing reaction maytake place in the presence of functional groups of at least one selectedfrom the class consisting of alkoxysilane, silanol and acyloxysilanegroups as well as epoxy groups with the aid of, as a curing catalyst, atleast one metal chelate compound selected from the class consisting ofaluminum chelate compounds, titanium chelate compounds and zirconiumchelate compounds and that the resulting cured film has excellentweather resistance, acid resistance and other physical properties.

The present invention is predicated on the above findings.

The high molecular weight hydroxy compound (A) to be used in invention Iis a compound containing an average of two or more hydroxyl groups permolecule and has a number average molecular weight of 3,000 to 200,000,preferably 5,000 to 80,000. If the number of hydroxyl groups is lessthan 2 on the average per molecule, the curing performance and the gelfraction ratio of the film will be decreased. From the standpoint ofweatherability and water resistance, the number of hydroxyl groups ispreferably not more than 400 on the average per molecule. If the numberaverage molecular weight of compound (A) is less than 3,000, the impactresistance, weatherability and other physical properties will not be asgood as desired. 0n the other hand, if the number average molecularweight exceeds 200,000, the compatibility of the compound with the othercomponents will be poor so that the uniformity of cure will besacrificed to detract from the weather resistance of the cured film.

As examples of the high molecular weight hydroxy compound (A), compoundsin the following categories (1) through (6) can be mentioned.

(1) High molecular weight acrylic polyol compounds: Homopolymers ofhydroxyl group-containing vinyl monomers (I) (for example, hydroxy-C₂ -₈alkyl esters of (meth) acrylic acid such as hydroxyethyl (meth) acrylatehydroxypropyl (meth) acrylate, etc. and adducts of such hydroxy-C₂ -₈alkyl esters of (meth) acrylic acid with lactones such asε-caprolactone, γ-valerolactone, etc.) and copolymers of said hydroxylgroup-containing vinyl monomers (I) with other α, β-ethylenicallyunsaturated monomers (II).

Examples of said α, β-ethylenically unsaturated monomers (II) include:

(a) Esters of acrylic acid or methacrylic acid: C₁ -₁₈ alkyl esters suchas methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate,butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, methylmethacrylate, ethyl methacrylate, propyl methacrylate, isopropylmethacrylate, butyl methacrylate, hexyl methacrylate, octylmethacrylate, lauryl methacrylate; C₂ -₁₈ alkoxyalkyl esters such asmethoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate,methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxybutylmethacrylate, etc.; C₂ -₈ alkenyl esters such as allyl acrylate, allylmethacrylate, etc.; C₃ -₁₈ alkenyloxyalkyl esters such as allyloxyethylacrylate, allyloxyethyl methacrylate and so on.

(b) Vinyl-aromatic compounds: styrene, α-methylstyrene, vinyltoluene,p-chlorostyrene and the like.

(c) Polyolefin compounds: butadiene, isoprene, chloroprene and so on.

(d) Others: acrylonitrile methacrylonitrile, methyl isopropenyl ketone,vinyl acetate, VeoVa monomers (Shell Chemical), vinyl propionate, vinylpivalate, acrylic acid, methacrylic acid and so on.

(2) High molecular weight polyester polyol compounds: The compoundsobtainable by esterifying polybasic acids (compounds containing 2 to 4carboxyl groups per molecule, such as-phthalic acid, isophthalic acid,terephthalic acid, maleic acid, pyromellitic acid and the correspondinganhydrides) with polyhydric alcohols (alcohols containing 2 to 6hydroxyl groups in the molecule, such as ethylene glycol, polyethyleneglycol, propylene glycol, neopentyl glycol, 1,6-hexanediol,trimethylolpropane, pentaerythritol, glycerol, tricyclodecanedimethanol,etc.). Aside from the above compounds, monobasic acids (for example,fatty acids such as castor oil fatty acid, soybean oil fatty acid, talloil fatty acid, linseed oil fatty acid, etc., benzoic acid and so on)can also be used if necessary.

(3) High molecular weight fluorine-containing polyol compounds:Copolymers of fluorine-containing (meth)acrylate monomers (III) (forexample, perfluorooctylethyl (meth)acrylate, perfluoroisononylethyl(meth)acrylate, etc.) with monomers (I); copolymers of monomers (I),(II) and (III); copolymers of fluorine-containing ethylene monomers withvinyl ethers (for example, copolymer of monochlorotrifluoroethylene,alkyvinyl ether and hydroxyalkylvinyl ether [Lumiflon, trademark ofAsahi Glass Co., Ltd.])

(4) High molecular weight polyurethane polyol compounds: Isocyanate-freepolymers obtainable by modifying said high molecular weight acrylicpolyol compounds, polyester polyol compounds, etc. with polyisocyanates(for example, tolylene diisocyanate, xylene diisocyanate, hexamethylenediisocyanate, isophorone diisocyanate, etc.)

(5) High molecular weight silicone polyol compounds: Alkoxysilane-,acyloxysilane- or silanol-free polymers obtainable by modifying saidhigh molecular weight acrylic polyol compounds, polyester polyolcompounds, etc. with silicone resins (for example, Z-6018 and Z-6188[both are products of Dow Corning], SH5050, SH6018 and SH6188 [all areproducts of Toray Silicone])

(6) Vinyl alcohol-styrene copolymers.

The epoxy compound (B) mentioned hereinbefore contains an average of 2or more epoxy groups per molecule and has a number average molecularweight of 120 to 200,000, preferably 240 to 80,000. If the number ofepoxy groups is less than 2, the curing performance and gel fractionratio will be decreased. From the standpoint of curing performance theaverage number of epoxy groups is preferably not more than 500 permolecule. Epoxy compounds with number average molecular weights lessthan 120are hardly available. On the other hand, if the number averagemolecular weight exceeds 200,000, the compatibility of the compound withthe other components is poor so that the weatherability of the curedfilm is sacrificed.

From the standpoint of curing performance, the epoxy compound (B)preferably has alicyclic epoxy groups. As specific examples of the epoxycompound (B), the following compounds can be mentioned. ##STR1## withpolyisocyanate compounds (i.e. organic diisocyanates such as aliphaticdiisocyanates, e.g. hexamethylene diisocyanate, trimethylhexamethylenediisocyanate, etc., alicyclic diisocyanates, e.g. hydrogenated xylylenediisocyanate, isophorone diisocyanate, etc., and aromatic diisocyanates,e.g. tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, etc.,adducts of such organic diisocyanates with polyalcohols, low molecularweight polyesters, water or the like, polymers of said respectiveorganic diisocyanates, and isocyanate biurets, etc.; representativecommercial products of these compounds include Burnock D-750, -800,DN-950, -970 and 15-455 (Dainippon Ink and Chemicals Inc.), Desmodur L,NHL, IL and N3390 (Bayer A. G., West Germany),. Takenate D-102, -202,-110N and -123N (Takeda Chemical Industries, Ltd.), Coronate L, HL, EHand 203 (Nippon Polyurethane Industry Co., Ltd.) and Duranate 24A-90CX(Asahi Chemical Industry Co., Ltd.); adducts of ##STR2## with polybasicacids; the compounds obtainable by oxidizing esters containingunsaturated groups such as ##STR3## esters obtainable by esterifyingtetrahydrophthalic anhydride, trimethylolpropane, 1,4-butanediol, etc.and having a number average molecular weight of about 900) withperacetic acid or the like.

Aside from the above compounds containing alicyclic epoxy groups,compounds having non-alicyclic epoxy groups, such as diglycidyl ether,2-glycidylphenyl glycidyl ether etc., can also be employed.

As the epoxy compound (B), homopolymers of the vinyl monomersrepresented by the following general formulas (1) through (16) andcopolymers thereof with the aforementioned α,β-ethylenically unsaturatedmonomers (II) can also be employed. ##STR4##

In the above respective general formulas, R₁ means a hydrogen atom or amethyl group; R₂ means a divalent aliphatic saturated hydrocarbon groupof 1 to 6 carbon atoms; R₃ means a divalent hydrocarbon group of 1 to 10carbon atoms, and T means an integer equal to 0 to 10, inclusive. In theabove formulas, the groups R₁ are the same or different, and so are thegroups R₂ and the groups R₃.

Among those epoxy group-containing vinyl monomers, the use of alicyclicepoxy group-containing vinyl monomers is preferred from the standpointof curing property. Thus, when an alicyclic epoxy group-containing vinylmonomer is employed, the addition reaction of the epoxy group to thehydroxyl group proceeds fast and the curing effect is improved.

As examples of the above divalent aliphatic saturated hydrocarbon groupsof 1 to 6 carbon atoms, straight-chain or branched alkylene groups suchas methylene, ethylene, propylene, tetramethylene, ethylethylene,pentamethylene, hexamethylene, etc. can be mentioned. As examples of thedivalent hydrocarbon group containing 1 to 10 carbon atoms, there may bementioned methylene, ethylene, propylene, tetramethylene, ethylethylene,pentamethylene, hexamethylene, decamethylene, phenylene, ##STR5## and soon.

As the epoxy compound (B), there may also be employed the compoundsobtainable by reacting any of said high molecular weight hydroxycompounds (A) with a compound containing one isocyanate group and oneepoxy group per molecule (for example, ##STR6## in the proportion ofmore than one mole of the latter compound to one hydroxyl group in theformer compound so as to react all the hydroxyl groups contained in thehydroxy compound (A).

The silane compound (C) is a compound containing an average of one ormore functional groups selected from the class consisting ofalkoxysilane, silanol and acyloxysilane groups (hereinafter referred tosimply as silane groups) per molecule. If the average number of silanegroups is less than 1, the curing performance and gel fraction ratio aredecreased. On the other hand, if too many silane groups are present, thereaction between silane group and epoxy group predominates to decreasethe number of epoxy groups available for reaction with hydroxyl groupsto thereby adversely affect the curing performance and gel fractionratio. Therefore, the number of silane groups in the molecule ispreferably not more than 2,500 on the average.

The silane compound (C) should have a number average molecular weight of104 to 200,000. Silane compounds with number average molecular weightsless than 104 are hardly available, while silane compounds with numberaverage molecular weights in excess of 200,000 are not well compatiblewith other components and fail to give weather-resistant cured films.

As the alkoxy groups in silane compounds (C), alkoxy groups containing 1to 6 carbon atoms are preferred. Thus, for example, methoxy, ethoxy,n-propoxy, isopropoxy and n-butoxy can be mentioned. As to acyloxygroups, those containing C₁ -₆ alkyl groups are preferred. Thus,acetoxy, propioxy, butyroxy, etc. can be mentioned by way of example.

As specific examples of silane compound (C), the following compounds (1)through (7) can be mentioned. (1) Compounds of general formulas (17)through (20). ##STR7## where all occurrences of R₄ may be the same ordifferent and each means a C₁₋₆ alkyl group or a phenyl group; alloccurrences of R₅ may be the same or different and each means a C₁₋₆alkyl group, a hydrogen atom or ##STR8## where R₆ is a C₁₋₆ alkyl group.

As examples of said C₁₋₆ alkyl group, there may be mentioned methyl,ethyl, n-propyl, iso-propyl, n-butyl, n-pentyl and n-octyl.

As examples of the compound of general formula (17), there may bementioned trimethylmethoxysilane, trimethylethoxysilane,triethylpropoxysilane, triphenylmethoxysilane, triphenylbutyloxysilane,trimethylsilanol and triphenylsilanol.

As examples of the compound of general formula (18), there may bementioned dimethyldimethoxysilane, dibutyldimethoxysilane,di-isopropyldipropoxysilane, diphenyldibutoxysilane,diphenyldiethoxysilane, diethyldisilanol, dihexyldisilanol and so on.

As examples of the compound of general formula (19), there may bementioned methyltrimethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, propyltrimethoxysilane, phenyltriethoxysilane,phenyltributoxysilane, hexyltriacetoxysilane, methyltrisilanol,phenyltrisilanol and so on.

Examples of the compound of general formula (20) includetetramethoxysilane, tetraethoxysilane, tetrapropoxysilane,tetracetoxysilane, diisopropoxydivaleroxysilane, tetrasilanol and so on.

Among these silane compounds, those having number average molecularweights from 104 to 40,000 are preferred and those in the range of 104to 30,000 are more desirable. Silane compounds with number averagemolecular weights less than 104 are not readily available, while silanecompounds with number average molecular weights exceeding 40,000 are notwell compatible with the other components so that the cured film doesnot have sufficient weather resistance.

(2) Homopolymers of compounds of general formula ##STR9## wherein Ameans ##STR10## R₇ means a hydrogen atom or a methyl group; R₈ means adivalent aliphatic saturated hydrocarbon group containing 1 to 6 carbonatoms; R₉ and R₁₀ may be the same or different and each means a hydroxylgroup, a phenyl group, an alkyl group of 1 to 6 carbon atoms, an alkoxygroup of 1 to 6 carbon atoms or an acyloxy group; R₁₁ means a hydrogenatom or an alkyl group of 1 to 6 carbon atoms; n is an integer equal to1 through 10, inclusive.

Referring to general formula (2), the divalent aliphatic saturatedhydrocarbon group of 1 to 6 carbon atoms, represented by R₈, is astraight-chain or branched alkylene group such as methylene, ethylene,propylene, tetramethylene, ethylethylene, pentamethylene, hexamethyleneand the like. The alkyl group of 1 to 6 carbon atoms, represented by R₉,R₁₀ and R₁₁, is a straight-chain or branched alkyl group such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl and so on. The alkoxygroup of 1 to 6 carbon atoms, represented by R₉ and R₁₀, is astraight-chain or branched alkoxy group such as methoxy, ethoxy,n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy,n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy and the like. Referring,further, to general formula (21), where n is not less than 2, alloccurrences of R₉ and R₁₀, respectively, may represent the same group ordifferent groups.

Among the compounds of general formula (21) which are used as monomersin the present invention, those in ##STR11## include, among others,γ-(meth)acryloxypropyltrimethoxysilane,γ-(meth)acryloxypropyltriethoxysilane,γ-(meth)acryloxypropyltripropoxysilane,γ-(meth)acryloxypropylmethyldimethoxysilane,γ-(meth)acryloxypropylmethyldiethoxysilane,γ-(meth)acryloxypropylmethyldipropoxysilane,γ-(meth)acryloxybutylphenyldimethoxysilane,γ-(meth)acryloxybutylphenyldiethoxysilane,γ-(meth)acryloxybutylphenyldipropoxysilane,γ-(meth)acryloxypropyldimethylmethoxysilane,γ-(meth)acryloxypropyldimethylethoxysilane,γ-(meth)acryloxypropylphenylmethylmethoxysilane,γ-(meth)acryloxypropylphenylmethylethoxysilane, ##STR12##γ-(meth)acryloxypropyltrisilanol, γ-(meth)acryloxypropylmethyldisilanol,γ-(meth)acryloxybutylphenyldisilanol,γ-(meth)acryloxypropyldimethylsilanol,γ-(meth)acryloxypropylphenylmethylsilanol, ##STR13## and so on.

Among the compounds of general formula (21), those ##STR14## include,among others, ##STR15## and so on. (3) Copolymers of compounds ofgeneral formula (21) with said α, β-ethylenically unsaturated monomers(II)

(4) Homopolymers of polysiloxane macromonomers (for example, themacromonomers described in Japanese Laid-open Patent Application KOKAINo. 275132/1987) which are obtainable by reacting 30 to 0.001 molepercent of a compound of general formula (21) with 70 to 99.999 molepercent of at least one of the compounds of general formulas (17)through (20) and having a number average molecular weight of 400 to100,000. The number average molecular weights of these homopolymers arepreferably in the range of 3,000 to 200,000, more preferably in therange of 5,000 to 80,000.

(5) Copolymers of said polysiloxane macromonomers with α,β-ethylenically unsaturated monomers (II). The number average molecularweights of these copolymers is preferably 3,000 to 200,000, morepreferably 5,000 to 80,000.

(6) Compounds obtainable by reacting a compound containing an isocyanatogroup and either an alkoxysilane group or an acyloxysilane group permolecule (for example, ##STR16## with said hydroxy compounds (A) in theratio of one mole of the former to one hydroxyl group in the hydroxycompounds (A) so as to react all the hydroxyl groups contained in (A).

(7) Compounds obtainable by reacting said compound containing anisocyanate group and either an alkoxysilane group or an acyloxysilanegroup per molecule with a polyhydric alcohol, which is used as astarting material for skid polyester polyol among said high molecularweight hydroxy compounds (A), in the ratio of one mole of the former toone hydroxyl group in the polyhydric alcohol, to react all the hydroxylgroups contained in the alcohol.

Among the above-mentioned various silane compounds (C), the polymersderived from polysiloxane macromonomers as mentioned above under (4) and(5) are particularly advantageous in that the cured film has a high gelfraction ratio and is superior in acid resistance, impact resistance andother physical properties.

The aforementioned high molecular weight compound (E) containing bothepoxy and silane groups, which is employed in Invention II, is acompound containing an average of 2 or more epoxy groups per moleculeand an average of 1 or more functional groups selected from the classconsisting of alkoxysilane, silanol and acyloxysilane groups (silanegroups) per molecule. If the number of epoxy or silane groups is lessthan the above-mentioned range, the curing performance and gel fractionratio will be decreased. On the other hand, if the number of silanegroups is too many, the epoxy groups are consumed as mentioned above toreduce the number of epoxy groups available for reaction with hydroxylgroups so that the curability of the resin composition is sacrificed.The average number of silane groups per molecule is preferably not morethan 2,500. From the standpoint of curability, the number of epoxygroups per molecule need not be more than 500 on the average. The numberaverage molecular weight of high molecular compound (E) is 3,000 to200,000, preferably 5,000 to 80,000. If the molecular weight is lessthan 3,000, curing performance and the weather resistance of the curedfilm will not be as good as desired. On the other hand, if the molecularweight of (E) exceeds 200,000, the compatibility thereof with the othercomponents will not be fully satisfactory. The alkoxy and acyloxy groupsin the alkoxysilane and acyloxysilane groups in high molecular weightcompound (E) may for example be those mentioned in connection with saidsilane compound (C).

As examples of high molecular weight compound (E), there may bementioned the following compounds.

(1) Copolymers obtainable by reacting said compound of general formula(21) or said polysiloxane macromonomer (such as these described injapanese Laid-open Patent Application KOKAI No. 275132/1987), which isobtainable by reacting a compound of general formula (21) with at leastone of the compounds of general formulas (17). through (20) in a ratioof 30 to 0.001 mole percent of the former to 70 to 99.999 mole percentof the latter and having a number average molecular weight of 400 to100,000, with said epoxy group-containing vinyl monomer of any ofgeneral formulas (1) through (16) and, if necessary, further with saidα, β-ethylenically unsaturated monomer (II)

(2) Compounds obtainable by reacting a high molecular weight hydroxycompound (A) containing an average of 3 or more hydroxyl groups permolecule, which can be prepared by adjusting the starting materials inthe synthesis of (A), said silane compound (C), which contains bothisocyanate and alkoxysilane or acyloxysilane groups in the molecule asmentioned under (7) in the listing of examples of (C), and a epoxycompound (B) containing both isocyanate and .epoxy groups in such amanner that the average number of epoxy groups per molecule will be atleast 2 and the average number of silane groups per molecule will be atleast 1.

(3) Homo- or co-condensates of compounds of general formulas ##STR17##wherein R₁₂ means a hydrogen atom or a methyl group; R₈, R₉, R₁₀ and R₁₁have the meanings respectively defined hereinbefore.

As examples of compounds of the above general formulas, there may bementioned γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriacetoxysilane,glycidoxymethyltrimethoxysilane, βglycidoxyethyltriethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltriethoxysilane,β-(3,4-epoxycycyclohexyl)ethyltriacetoxysilane,γ-(3,4-epoxycyclohexyl)propyltriethoxysilane and so on.

Among the above high molecular weight compounds (E), the copoplymersobtained by using polysiloxane macromonomers as mentioned under (1) areparticularly advantageous in that the resultant film is high in gelfraction ratio, acid resistance and impact resistance.

The high molecular weight compound (F) containing hydroxyl and silanegroups, which is employed in Invention III, is a compound containing anaverage of two or more hydroxyl groups per molecule and an average of atleast one functional group selected from the class consisting ofalkoxysilane, silanol and acyloxysilane groups (silane groups) permolecule. If the number of hydroxyl or silane groups is less than theabove range, curing performance and gel fraction ratio are not as goodas desired,. From the standpoint of weather resistance and waterresistance, the number of hydroxyl groups per molecule is preferably notmore than 400. The number of silane groups is preferably not more than2,500 per molecule from the standpoint of curing performance and gelfraction ratio. The number average molecular weight of high molecularweight compound (F) is 3,000 to 200,000, preferably 5,000 to 80,000. Ifthe molecular weight is less than 3,000, the weather resistance of thecured film will not be fully satisfactory. On the other hand, if thenumber average molecular weight exceeds 200,000, the compatibility withthe other components will not be as good as desired. The alkoxy andacyloxy moieties of the alkoxysilane and acyloxysilane groups containedin high molecular weight compounds (F) may for example be thecorresponding groups mentioned for silane compound (C) hereinbefore.

As examples of high molecular compound (F), the following compounds maybe mentioned.

(1) Copolymers obtainable by reacting said hydroxyl group-containingvinyl monomer (I) with said compound of general formula (21) and/or saidpolysiloxane macromonomer (such as those mentioned in Japanese Laid-openPatent Application KOKAI No. 275132/1987) and, if necessary, furtherwith said α, β-ethylenically unsaturated monomer (II).

(2) Compounds obtainable by reacting a high molecular weight hydroxylcompound (A) containing an average of 3 or more hydroxyl groups permolecule with a compound containing both isocyanate and silane groups inthe molecule as mentioned under (7) in the list of examples of silanecompound (C) in such a manner that the average number of hydroxyl groupsper molecule is at least 2 and the average number of silane groups permolecule is at least 1.

Of the above-mentioned high molecular weight compounds (F), thecopolymers prepared using polysiloxane macromonomers as mentioned under(1) are particularly advantageous in that the resulting film is superiorin gel fraction ratio, acid resistance, impact resistance and otherphysical properties.

The low molecular weight epoxy compound (G) is a compound containing anaverage of 2 or more epoxy groups per molecule. If the average number ofepoxy groups per molecule is less than 2, curing performance and gelfraction ratio will not be as good as desired. The number of epoxygroups per molecule is preferably not more than 500 from the standpointof curability. The number average molecular weight of low molecularweight epoxy compound (G) 240 to 5,000, preferably 240 to 2,000.Compounds (G) with number average molecular weights less than 240 arenot readily available, while compounds with molecular weights over 5,000are not sufficiently compatible with the other components. As specificexamples of low molecular weight epoxy compound (G), the low molecularweight epoxy compounds among the examples of said epoxy group containingcompound (B) can be mentioned.

The high molecular weight compound (H) containing both hydroxyl andepoxy groups, which is employed in invention IV, is a compoundcontaining an average of 2 or more hydroxyl groups per molecule and anaverage of 2 or more epoxy groups per molecule. If the number ofhydroxyl groups or that of epoxy groups is less than the above range,curability will be adversely affected. From the standpoint of weatherresistance, water resistance, etc., the number of hydroxyl groups permolecule is preferably not more than 400. From the standpoint ofcurability, the average number of epoxy groups is preferably not morethan 500 per molecule. The number average molecular weight of highmolecular weight compound (H) is 3,000 to 200,000, preferably 5,000 to80,000. If the molecular weight is less than 3,000, weather resistancewill not be as high as desired. On the other hand, if the molecularweight exceeds 200,000, the compatibility with the other components willbe poor.

As the high molecular weight compound (H), the following compounds can,for example, be employed.

(1) Copolymers obtainable by reacting said hydroxyl group-containingvinyl monomer (I) with any of said epoxy group-containing vinyl monomersof general formulas (1) through (16) and, if necessary, further withsaid α, β-ethylenically unsaturated monomer (II)

(2) Compounds obtainable by reacting said high molecular weight hydroxycompound (A) containing an average of 3 or more hydroxyl groups permolecule with said epoxy group-containing compound (B) containing bothisocyanate and epoxy groups in the molecule in such a manner that theaverage number of hydroxyl groups per molecule will be at least 2 andthe average number of epoxy groups will be at least 2.

The silane compound (C) is the same as the silane compound mentioned forInvention I. Among those silane compounds, copolymers obtained by usingpolysiloxane macromonomers as described under (4) or (5) in the list ofexamples of (C) given hereinbefore are particularly advantageous in thatnot only a high gel fraction ratio but also excellent acid resistance,impact resistance and other physical properties can be obtained.

The components described hereinabove can be respectively provided by theknown methods. Thus, the reaction between hydroxyl and isocyanategroups, the condensation reaction of silane groups, copolymerizationreaction and other reactions can all be conducted in the known manners.For example, the reaction between isocyanate and hydroxyl groups can beadvantageously carried out at a temperature between room temperature and130° C over a period of about 30 to 360 minutes. The condensationreaction of silane groups can be carried out in the presence of an acidcatalyst (for example, hydrochloric acid, sulfuric acid, formic acid,acetic acid, etc.) at an elevated temperature of about 40° to 150° C.for about 1 to 24 hours. The copolymerization reactions can be carriedout under the same conditions as those used generally in the productionof acrylic or vinyl resins. In an exemplary synthetic process, therespective monomers are dissolved or dispersed in an organic solvent andin the presence of a radical polymerization initiator, the solution orsuspension is heated at a temperature of about 60° to 180° C. withconstant stirring. The reaction time generally ranges from about 1 to 10hours. As the organic solvent, the aforementioned alcohol, ether, esteror hydrocarbon solvent can be selectively employed. A hydrocarbonsolvent is preferably used in combination with a different type ofsolvent from the standpoint of solubility. As the radical initiator, anyof usual initiators can be employed. Thus, it may be any of variousperoxides such as benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate,etc., and azo compounds such as azobisisobutyronitrile,azobisdimethylvaleronitrile and so on.

As the crosslinking agent, at least one of chelate compounds (D) ofaluminum, titanium or zirconium is employed in the present invention.Preferred is a chelate compound containing a compound which showsketo-enol tautomerism as a ligand forming a stable chelate ring.

As examples of said compound which shows keto-enol tautomerism, theremay be mentioned β-diketones (acetylacetone etc.), acetoacetic acidesters (methyl acetoacetate etc.), malonic acid esters (ethyl malonateetc.), ketones having a hydroxyl group in the β-position (diacetonealcohol etc.), aldehydes having a hydroxyl group in the βposition(salicylaldehyde etc.), esters having a hydroxyl group in the β-position(methyl salicylate etc.) and so on. Particularly satisfactory resultsare obtained when acetoacetic esters and β-diketones are employed.

The aluminum chelate can be easily prepared by mixing generally one moleequivalent of an aluminum alkoxide of the general formula ##STR18##wherein all occurrences of R₁₃ may be the same or different and eachmeans an alkyl group of 1 to 20 carbon atoms or an alkenyl group withabout 1 to 3 mole equivalents of a compound which, as aforesaid, showsketo-enol tautomerism, if necessary with heating.

The alkyl group containing 1 to 20 carbon atoms include, in addition tothe C₁ -₆ alkyl groups mentioned hereinbefore, heptyl, octyl, nonyl,decyl, undecyl, dodecyl, tridecyl, tetradecyl, octadecyl and so on. Asexamples of said alkenyl group, there may be mentioned vinyl, allyl andso on.

As examples of the aluminum alkoxide of general formula (22), there maybe mentioned aluminum trimethoxide, aluminum triethoxide, aluminumtri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide,aluminum triisobutoxide, aluminum tri-secbutoxide, aluminumtri-tert-butoxide and so on. Particularly preferred are aluminumtriisopropoxide, aluminum tri-sec-butoxide and aluminum tri-n-butoxide.

The titanium chelate can be prepared, for example by mixing generallyone mole equivalent, as titanium, of a titanate compound of the generalformula ##STR19## wherein m represents an integer equal to 0 through 10,inclusive, and R₁₃ has the same meaning as defined hereinbefore, withabout 1 to 4 mole equivalents of a compound which, as aforesaid, showsketo-enol tautomerism, if necessary with heating.

As examples of the titanate of general formula (23) wherein m is equalto 0, there may be mentioned, among others, tetramethyl titanate,tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate,tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert -butyltitanate, tetra-n-pentyl titanate, tetra-n-hexyl titanate, tetraisooctyltitanate, tetra-n-lauryl titanate and so on. Particularly useful aretetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanateand tetra-tert-butyl titanate. As to the titanate of general formula(23) wherein m is 1 or more, the dimers to undecamers (m=1 to 10) oftetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanateor tetra-tert-butyl titanate are preferred.

The zirconium chelate can be prepared, for example by mixing generallyone mole equivalent, as zirconium, of a zirconate compound of thegeneral formula: ##STR20## wherein m and R₁₃ are as definedhereinbefore, with about 1 to 4 mole equivalents of said compound whichshows keto-enol tautomerism, if necessary with heating.

As examples of the zirconate of general formula (24) wherein m is equalto 0, there may be mentioned tetraethyl zirconate, tetra-n-propylzirconate, tetraisopropyl zirconate, tetraisobutyl zirconate,tetra-n-butyl zirconate, tetra-sec-butyl zirconate, tetra-tert-butylzirconate, tetra-n-pentyl zirconate, tetra-tert-pentyl zirconate,tetra-tert-hexyl zirconate, tetra-n-heptyl zirconate, tetra-n-octylzirconate, tetra-n-stearyl zirconate and so on. Particularly preferredare tetraisopropyl zirconate, tetra-n-propyl zirconate, tetraisobutylzirconate, tetra-n-butyl zirconate, tetra-sec-butyl zirconate andtetra-tert-butyl zirconate. As to the zirconate of general formula (24)wherein m is equal to 1 or more, the dimers to undecamers (m=1 to 10) oftetraisopropyl zirconate, tetra-n-propyl zirconate, tetra-n-butylzirconate, tetraisobutyl zirconate, tetra-sec-butyl zirconate ortetratert-butyl zirconate are preferred. The zirconium chelate compoundmay contain an association of such zirconates as a constituent unit.

Among preferred chelate compounds for purposes of this invention aresuch aluminum chelate compounds as tris(ethylacetoacetate)aluminum,tris(n-propylacetoacetate)aluminum, tris(isopropylacetoacetate)aluminum,tris(n-butylacetoacetate)aluminum,isopropoxybis(ethylacetoacetate)aluminum,diisopropoxyethylacetoacetatealuminum, tris(acetylacetonato)aluminum,tris(propionylacetonato)aluminum, disopropoxypropionylacetonatoaluminum,acetylacetonatobis(propionylacetonato)aluminum,monoethylacetoacetatebis(acetylacetonato)aluminum,monoacetylacetonatobis(ethylacetoacetate)aluminum, etc., such titaniumchelate compounds as diisopropoxybis(ethylacetoacetate)titanium,diisopropoxybis(acetylacetonato)titanium, etc., and such zirconiumchelate compounds as tetrakis(acetylacetonato)zirconium,tetrakis(n-propylacetoacetate)zirconium,tetrakis(ethylacetoacetate)zirconium and so on.

If, in the practice of this invention, unchelated alkoxy compounds ofaluminum, titanium or zirconium of general formulas (22) through (24),are used as crosslinking agents, the pot life is shortened so that theresulting composition cannot be used as a one-package composition.

As the chelate compound to be used as a crosslinking agent in thepresent invention, the above-mentioned respective chelate compounds ofaluminum, zirconium and titanium can be used either singly or incombination.

In the resin composition of Invention I, the proportions of highmolecular weight hydroxy compound (A) and epoxy compound (B) are 5 to 95weight percent, preferably 20 to 80 weight percent, for the former and95 to 5 weight percent, preferably 80 to 20 weight percent, for thelatter, both based on the combined weight of (A) and (B). If the ratioof the two compounds are outside the above range, low-temperaturecurability will not be as good as desired. Based on 100 weight parts ofhigh molecular weight hydroxy compound (A) and epoxy compound (b)combined, the silane compound (C) is used in a proportion of 0.1 to 50parts by weight, preferably 1 to 20 parts by weight. If the proportionof silane compound (C) is less than 0.1 part by weight, curingperformance will be adversely affected. On the other hand, use of (C) inexcess of 50 parts by weight is also disadvantageous in that the solventresistance of the film will be adversely affected by the residue ofsilane compound (C). The metal chelate compound (D) is used in aproportion of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts byweight, based on 100 parts by weight of high molecular weight hydroxycompound (A) and epoxy compound (B) combined. If the proportion of metalchelate compound (D) is less than 0.01 part by weight, curingperformance will be adversely affected, while the use of (D) in excessof 10 parts by weight will result in reduced water resistance of thecured film.

In the resin composition of Invention II, the proportion of highmolecular weight hydroxy compound (A) is 5 to 95 weight percent,preferably 20 to 80 weight percent and that of high molecular weightcompound containing both epoxy and silane groups (E) is 95 to 5 weightpercent, preferably 80 to 20 weight percent, both based on the combinedamount of (A) and (E). If the ratio of the two components is outside theabove range, the curing performance, particularly low-temperaturecurability, of the composition will not be as good as desired. The metalchelate compound (D) is used in a proportion of 0.01 to 10 parts byweight, preferably 0.1 to 5 parts by weight based on 100 parts by weightof said high molecular weight hydroxy compound (A) and high molecularweight compound containing both epoxy and silane groups (E) combined. Ifthe proportion of metal chelate compound (D) is less than 0.01 part byweight, the curability of the composition will not be as good asdesired, while the use of (D) in excess of 10 parts by weight willresult in reduced water resistance of the cured film.

in the resin composition of Invention III, said high molecular weightcompound containing both hydroxyl and silane groups (F) is used in aproportion of 5 to 10 95 weight percent, preferably 20 to 80 weightpercent and said lower molecular weight epoxy compound (G) in aproportion of 95 to 5 weight percent, preferably 80 to 20 weight percentbased on the combined weight of (F) and (G). If the ratio of the twocompounds is outside the above range, the curing performance,particularly low-temperature curability, of the composition will not befully satisfactory. The metal chelate compound (D) is used in aproportion of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts byweight based on 100 parts by weight of said high molecular weightcompound containing both hydroxyl and silane groups (F) and lowmolecular weight epoxy compound (G) combined. If the proportion of metalchelate compound (D) is less than 0.01 part by weight, curingperformance will not be satisfactory, while the use of (D) in excess of10 parts by weight will detract from the water resistance of the film.

In the resin composition of Invention IV, said high molecular weightcompound containing both hydroxyl and epoxy groups (H) is used in aproportion of 5 to 95 weight percent, preferably 20 to 80 weight percentand said silane compound (C) in a proportion of 95 to 5 weight percent,preferably 80 to 20 weight percent based on the combined weight of (H)and (C). If the ratio of the two compounds is outside the above range,the curing performance, particularly low-temperature curability, of thecomposition will not be as good as desired. The metal chelate compound(D) is used in a proportion of 0.01 to 10 parts by weight, preferably0.1 to 5 parts by weight based on 100 parts by weight of said highmolecular weight compound containing both hydroxyl and epoxy groups (H)and silane compound (C) combined. If the proportion of metal chelatecompound (D) is less than 0.01 part by weight, curability will not be asgood as desired, while the incorporation of (D) in excess of 10 parts byweight will result in reduced water resistance of the cured film.

If necessary, inorganic and organic pigments may be incorporated in theresin compositions of the present invention. As examples of theinorganic pigment, there may be mentioned oxide pigments (such astitanium dioxide, red iron oxide, chromium oxide, etc., hydroxidepigments (such as alumina white etc.), sulfate pigments (such asprecipitated barium sulfate, clay etc.), carbonate pigments (such asprecipitated calcium carbonate etc.), carbon pigments (such as carbonblack etc.), and various metal powders (such as aluminum powder, bronzepowder, zinc dust, etc.). As examples of said organic pigments, azocolors (such as lake red, fast yellow, etc.) and phthalocyanine colors(such as phthalocyanine blue etc.) can be mentioned.

If necessary, the resin compositions of the present invention can beused as dissolved in organic solvents.

From the standpoint of curing rate of the resin composition, an organicsolvent having a boiling point not exceeding about 150° is preferred,although this is not an essential requirement. Preferred organicsolvents include hydrocarbon solvents such as toluene, xylene, etc.,ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone,etc., ester solvents such as ethyl acetate, butyl acetate, etc., ethersolvents such as dioxane, ethylene glycol diethyl ether, etc., andalcohol solvents such as butanol, propanol and so on. While thesesolvents may be used alone or in suitable combination, alcohol solventsare preferably used in combination with other kinds of solvents from thestandpoint of solubility of the resin. While the resin concentrationvaries with different applications, it is generally about 10 to 70weight percent.

The resin compositions of the present invention can be used withadvantage in such applications as coatings, adhesives, inks and so on.

When any of the resin compositions of the present invention is to beused as a coating material, it can be applied by any routine coatingmethod, such as spray coating, roll coating or brush coating.

The resin compositions of the present invention can be easily cured at alow temperature not exceeding 100° C. and even at room temperaturewithout heating. In the latter case, complete cure can be achievedgenerally in about 8 hours to about 7 days. When the curing reaction isconducted at an elevated temperature of about 40° to 100° C., completecure occurs in as short as about 5 minutes to about 3 hours.

The reason why the resin compositions of the present invention haveexcellent low-temperature curalibity seems to be as follows. In thefirst place, the metal chelate compound reacts with the silane group togive the following bond. ##STR21##

Then, this bond is coordinated to the silanol group (the alkoxysilaneand acyloxysilane groups are converted to silanol group by humidity inthe atmosphere) to polarize the silanol group as follows. ##STR22##

polarized silanol group reacts with the epoxy group to give the bond:##STR23##

The epoxy group then reacts with a hydroxyl group to give: ##STR24##

This reaction between the epoxy and hydroxyl groups proceeds at acomparatively low temperature.

Since the compositions of the present invention contain a hydroxylgroup-containing compound as an essential component and, in addition,contains epoxy and silane groups and, further, a metal chelate compound,the above reaction appears to proceed very rapidly to insure excellentlow-temperature curability.

The resin compositions of the present invention can be implemented byusing the respective components in rather liberal proportions.Therefore, the cured product tailored to the intended use can beobtained by mixing the components in suitable proportions beforeapplication. By way of illustration, Invention I may be implemented, forexample, by a process in which said high molecular weight hydroxycompound (A) as a main component is cured with said epoxy compound (B),silane compound (C) and metal chelate compound (D), a process in whichsaid epoxy compound (B) as a main component is cured with said highmolecular weight hydroxy compound (A), silane compound (C) and metalchelate compound (D), or a process in which said silane compound (C) asa main component is cured with said hydroxy compound (A), epoxy compound(B) and metal chelate compound (D).

If a pigment, such as titanium white, is dispersed using a resincontaining epoxy, hydroxyl and silano groups, the silanol groupscontained in the resin will react with Al₂ 0₃, SiO₂ and ZnO, inclusiveof their hydrates, on the surface of the pigment (titanium white) toincrease the thickness of the resin system or give rise to coarseparticles and the metal chelate compound is also liable to react withsuch metal oxides and hydrates on the surface of titanium white toincrease the viscosity of the system. On the other hand, in the resincompositions of the present invention, the above problem can be obviatedby dispersing the pigment titanium white using said high molecularweight hydroxy compound (A).

The resin compositions of the present invention insure the followingadvantageous effects.

1. A highly weather-resistant film can be obtained.

2. Since the curing component can be easily modified, various filmstailored to intended uses can be obtained.

3. The curing reaction proceeds smoothly at low temperatures notexceeding about 100° C.

4. The composition has a long pot life and can be used as a one-packagecoating.

5. The cured film has excellent acid resistance.

The following examples are further illustrative of the presentinvention.

PRODUCTION EXAMPLE

1. Production of compound (a)

    ______________________________________                                         ##STR25##                 200    g                                           γ-Methacryloxypropyltrimethoxysilane                                                               100    g                                           n-Butyl acrylate           700    g                                           Azobisisobutyronitrile     10     g                                           ______________________________________                                    

The above starting materials were blended and the mixture was addeddropwise to 1,000 g of xylene at a temperature of 110° C. to give anacrylic resin with a number average molecular weight of 30,000 (theaverage number of epoxy groups per molecule =30 and that of alkoxysilanegroups =12).

2. Production of compound (b)

    ______________________________________                                        Methyltrimethoxysilane  2720 g                                                γ-Methacryloxypropyltrimethoxysilane                                                             256 g                                                Deionized water         1134 g                                                30% Hydrochloric acid     2 g                                                 Hydroquinone              1 g                                                 ______________________________________                                    

The above mixture was reacted at 80° C. for 5 hours. The resultingpolysiloxane macromonomer had a number average molecular weight of 2,000and contained one vinyl group (polymerizable unsaturated bond) and 4hydroxyl groups on the average per mol.

    ______________________________________                                        The above macromonomer                                                                            300 g                                                     (nonvolatile matter)                                                          Styrene             100 g                                                     Glycidyl methacrylate                                                                             100 g                                                     n-Butyl acrylate    500 g                                                     Azobisisobutyronitrile                                                                             20 g                                                     ______________________________________                                    

The above mixture was added dropwise to 1,000 g of xylene andpolymerized at 120° C. to give a clear copolymer. The above copolymercontained an average of 12 silanol groups and an average of 14 glycidylgroups per molecule and had a number average molecular weight of about20,000.

3. Production of compound (c)

    ______________________________________                                        Trimethylolpropane                                                                              268 g                                                       1,6-Hexanediol    118 g                                                       Phthalic anhydride                                                                              422 g                                                       ______________________________________                                    

The above mixture was subjected to co-condensation under heating anddehydration to give a polyester polyol.

To 500 g of the above polyester polyol were added 306 g of ##STR26## and0.17 g of dibutyltin laurate and the reaction was conducted at 80° C.for 3 hours. The procedure gave a compound containing an average of 5.5epoxy groups per molecule and an average of 1.4 alkoxysilane groups permolecule.

4. Production of compound (d)

    ______________________________________                                         ##STR27##               520    g                                             Deionized water          54     g                                             Ethanol                  574    g                                             1N-Hydrochloric acid     1.5    g                                             ______________________________________                                    

The above mixture was reacted at 50° C. for 6 hours to give anoligocondensate of silane monomer containing an average of 18alkoxysilane groups and an average of 14 epoxy groups per molecule.

5. Production of compound (e)

    ______________________________________                                         ##STR28##                                                                                                600    g                                          n-Butyl methacrylate        400    g                                          Azobisiobutyronitrile       10     g                                          ______________________________________                                    

The above mixture was added dropwise to 1,000 g of xylene at 100° C. forpolymerization. The procedure gave a compound containing an average of51 epoxy groups per molecule and having a number average molecularweight of 35,000.

6. Production of compound (f)

    ______________________________________                                        2-Hydroxyethyl acrylate    116    g                                            ##STR29##                 196    g                                           2-Ethylhexyl methacrylate  688    g                                           Azobisiobutyronitrile      10     g                                           ______________________________________                                    

The above mixture was added dropwise to 1,000 g of xylene at 100° C. forpolymerization. The procedure gave a compound having a number averagemolecular weight of 30,000.

This compound contained an average of 30 epoxy groups and an average of30 hydroxyl groups per molecule.

7. Production of compound (g)

A mixture of 300 g (nonvolatile matter) of the polysiloxane macromonomerprepared in the production of compound (b), 100 g of styrene, 600 g ofn-butyl acrylate and 20 of azobisisobutyronitrile was added dropwise to1,000 g of xylene at 120° C. for polymerization. The procedure gave aclear copolymer. This copolymer contained an average of 12 silanolgroups per molecule and had a number .average molecular weight of about20,000.

EXAMPLE 1

A resin composition was provided by mixing 100 g of an acrylic polyol(2-hydroxyethyl acrylate/n-butylmethacrylate/styrene/azobisisobutyronitrile =116 g/734 g/150 g/10 g)containing an average of 30 hydroxyl groups per molecule and having anumber average molecular weight of 30,000 with

    ______________________________________                                         ##STR30##                  20    g                                           Triphenylsilanol            1     g                                           tris(Acetylacetonato)aluminum                                                                             0.5   g.                                          ______________________________________                                    

EXAMPLE 2

A resin composition was provided by mixing 100 g of the same acrylicpolyol as used in Example 1 with 30 g (nonvolatile matter) of thecopolymer prepared in the production of compound (g), 20 g of ##STR31##

EXAMPLE 3

A resin composition was provided by mixing 100 g of a polyester polyol(phthalic anhydride/neopentyl glycol/trimethylolpropane =550 g/211 g/239g) containing an average of 18 hydroxyl groups per molecule and having anumber average molecular weight of 10,000 with 100 g (nonvolatilematter) of compound (a) and 1 g ofdiisopropoxybis(ethylacetoacetate)titanium.

EXAMPLE 4

A resin composition was provided by mixing 166 g of Lumiflon LF-200(trademark of Asahi Glass Co., Ltd., with an average of 18.5 hydroxylgroups per molecule and a number average molecular weight of 20,000)(nonvolatile matter 60 wt. %) with 80 g (nonvolatile matter) of compound(b) and 0.5 g of tetrakis (ethylacetoacetate) zirconium.

EXAMPLE 5

A resin composition was provided by mixing 100 g of an acrylic polyol(2-hydroxyethyl methacrylate/n-butyl acrylate/methylmethacrylate/azobisisobutyronitrile =650 g/175 g/175 g/10 g) containingan average of 150 hydroxyl groups per molecule and having a numberaverage molecular weight of 30,000 with 900 g (nonvolatile matter) ofcompound (c) and 1.8 g of tris(ethylacetoacetate) aluminum.

EXAMPLE 6

A resin composition was provided by mixing 100 g of the same acrylicpolyol as used in Example 1 with 30 g (nonvolatile matter) of compound(d) and 1.2 g of

EXAMPLE 7

    ______________________________________                                        2-Hydroxyethyl acrylate 120 g                                                 γ-Methacryloxypropyltrimethoxysilane                                                             20 g                                                 n-Butyl methacrylate    860 g                                                 Azobisisobutyronitrile   5 g                                                  ______________________________________                                    

The above mixture was added dropwise to 1,000 g of a 50:50 (w/w) mixtureof xylene and n-butanol at 100° C. for polymerization. The proceduregave a high molecular weight compound containing an average of 46hydroxyl groups and an average of 11 alkoxysilane groups per moleculeand having a number average molecular weight of 45,000. A resincomposition was provided by mixing 200 g of the above reaction productwith 40 g (nonvolatile matter) of compound (e) and 1.2 g oftris(acetylacetonato)aluminum.

EXAMPLE 8

    ______________________________________                                        2-Hydroxyethyl acrylate 120 g                                                 Polysiloxane macromonomer,                                                                            130 g                                                 prepared in production of compound (b)                                        (nonvolatile matter)                                                          n-Butyl methacrylate    750 g                                                 Azobisisobutyronitrile   5 g                                                  ______________________________________                                    

The above mixture was added dropwise to 1,000 g of a 50:50 (w/w) mixtureof xylene and n-butanol at 100° C. for polymerization. The proceduregave a high molecular weight compound containing an average of 46hydroxyl groups and an average of 12 silanol groups per molecule andhaving a number average molecular weight of 48,000. A resin compositionwas provided by mixing 200 g of the above reaction product with 40 g(nonvolatile matter) of compound (e) and 1.2g oftris(acetylacetonato)aluminum.

EXAMPLE 9

A resin composition was provided by mixing 50 g (nonvolatile matter) ofcompound (g) with 100 g (nonvolatile matter) of compound (f) and 1.0 gof tetra-kis(ethylacetoacetate)zirconium.

EXAMPLE 10

To 100 g of the same acrylic polyol as used in Example 1 was added 500 gof titanium white CR-93(trademark of ishihara Sangyo Co., Ltd., titaniumdioxide) and the mixture was dispersed on a shaker. To this dispersionwere added 800 g (nonvolatile matter) of compound (a) and 5 g of tris(acetylacetonato) aluminum. The resultant composition was a satisfactorydispersion with a particle size of 5 μm (determined in accordance withASTM D 1201-64).

Comparative Example 1

A resin composition was provided by adding 30 g of Cymel 303 (trademarkof American Cyanamid Company, a methoxysilane resin) to 100 g of thesame polyester polyol as used in Example 3.

Comparative Example 2

A resin composition was provided by adding 20 g of Burnock DN-990(trademark of Dainippon Ink and Chemicals Co., Ltd., a diisocyanatecompound; 90 wt. %) to 100 g of the same polyester polyol as used inExample 3.

[Film performance tests]

Each of the resin compositions prepared in Examples 1 through 10 andComparative Examples 1 and 2 was coated in a dry thickness of 100 μm(provided, however, that a thickness of 50 μm was used for waterresistance test and weatherability test) and cured at 80° C. for 10minutes, and the cured film was subjected to various tests.

Gel fraction ratio:

The dry film was peeled off from the glass substrate and extracted withrefluxing acetone in a Soxhlet extractor for 6 hours. The gel fractionratio was expressed in % residue of the film. Impact resistance: Mildsteel sheet was used as the substrate. Using a DuPont impact tester, aweight of 500 g (impact core diameter of 1/2 inch) was dropped on thecoated surface and the maximum dropping distance (cm) which did notcause cracking or exfoliation of the coat was determined.

Water resistance:

Mild steel sheet was used as the substrate. The testpiece was immersedin lukewarm water (40° C.) for 60 days to check for abnormalities(blisters, whitening, loss of gloss) in the film. Weatherability:Aluminum sheet was used as the substrate. Using the QUV weather-o-meter(The Q-Panel Co., Ltd.; a fluorescent lamp No. QFS-40, UV-B, awavelength range of 320-280 nm), an irradiation (60° C., 8hours)-condensation (50° C., 4 hours) cycle was repeated for 2000 hoursand the degree of film degradation was grossly evaluated.

Acid resistance:

Glass plate was used as the substrate. The testpiece was immersed in 40%aqueous H₂ SO₄ (40° and 60° C.) for 5 hours and the appearance (gloss,whitening) of the coated surface was grossly evaluated. Coated surfacecondition: Mild steel sheet was used as the substrate. The film waschecked for loss of gloss, shrinkage, cracks, exfoliation, pigmentgrains. Pot life: Each composition was allowed to stand in an openvessel in an environment of 20° C. and 70% R. H. and the time periodduring which no viscosity increase took place was determined.

The results of the above tests are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                                         Comparative                     Examples                                      Examples                        1    2   3    4   5    6    7    8   9   10   1    2                   __________________________________________________________________________    Gel fraction                                                                         90.3 94.6                                                                              90.2 98.5                                                                              94.2 98.0 95.9 98.9                                                                              97.0                                                                              90.5 76.0 96.8                ratio                                                                         Impact 40   50< 40   50< 40   50   50   50< 50< 40   40   50                  resistance                                                                    Water  Good Good                                                                              Good Good                                                                              Good Good Good Good                                                                              Good                                                                              Good Poor Good                resistance                                                                    Weather-                                                                             Good Good                                                                              Good Good                                                                              Good Good Good Good                                                                              Good                                                                              Good Poor Poor                ability                                                                       Acid                                                                          resistance                                                                    40° C.                                                                        Good Good                                                                              Good Good                                                                              Good Good Good Good                                                                              Good                                                                              Good Marked                                                                             Good                                                                     decrease                                                                      in gloss                 60° C.                                                                        Slight                                                                             Good                                                                              Slight                                                                             Good                                                                              Slight                                                                             Very Slight                                                                             Good                                                                              Good                                                                              Slight                                                                             Marked                                                                             Decrease                   decrease decrease decrease                                                                           slight                                                                             decrease     decrease                                                                           decrease                                                                           in gloss                   in gloss in gloss in gloss                                                                           decrease                                                                           in gloss     in gloss                                                                           in gloss                                               in gloss                                        Coated sur-                                                                          Good Good                                                                              Good Good                                                                              Good Good Good Good                                                                              Good                                                                              Good Good Good                face condition                                                                Pot life                                                                             150< 150<                                                                              150< 150<                                                                              150< 150< 150< 150<                                                                              150<                                                                              150< 150< 10>                 __________________________________________________________________________

What is claimed is:
 1. A resin composition comprising 5 to 95 weight percent of (H), a high molecular weight compound containing an average of 2 or more hydroxyl groups and an average of 2 or more epoxy groups per molecule and having a number average molecular weight of 3,000 to 200,000; 95 to 5 weight percent of (C), a silane compound containing an average of 1 or more functional groups selected from the group consisting of alkoxysilane, silanol and acyloxysilane groups and having a number average molecular weight of 104 to 200,000; and 0.01 to 10 parts by weight of (D), at least one metal chelate compound selected from the group consisting of aluminum chelate compounds, titanium chelate compounds and zirconium chelate compounds per 100 parts by weight of the combined weights of (H) and (C).
 2. A resin composition according to claim 1 wherein said high molecular weight compound (H) contains an average of 2 to 400 hydroxyl groups and an average of 2 to 500 epoxy groups per molecule and said silane compound (C) contains an average of 1 to 2,500 said functional groups. 